Ethernet is a communication standard that provides compatibility with several different data rate sub-standards that are suitable for different network bandwidths. Each generation of Ethernet typically provides a default data rate that is many orders of magnitude higher than a prior generation. The supporting communications infrastructure, such as cable and/or other media to transport signals, often lags behind the new generation, and may not be able to support the higher data rates. Reverse compatibility with older generation data rates is thus important.
While legacy compatibility for Ethernet enables new generation hardware to function with older infrastructure, the gap between the legacy data rates and new generation default data rates may be significant. For example, Ethernet transceivers that have the capability to operate at 10 Gb/s may need to operate at one-tenth that rate, to 1 Gb/s, as the next highest supported data rate. In many cases, while a given infrastructure may be unable to support a full 10 Gb/s data rate, the infrastructure may still be able to support a rate that far exceeds 1 Gb/s.